Astrophysical tests of modified gravity: Stellar and gaseous rotation curves in dwarf galaxies
Bibliographic record
Abstract
Chameleon theories of gravity predict that the gaseous component of isolated dwarf galaxies rotates with a faster velocity than the stellar component. In this paper, we exploit this effect to obtain new constraints on the model parameters using the measured rotation curves of six low surface brightness galaxies. For $f(R)$ theories, we rule out values of ${f}_{R0}>{10}^{\ensuremath{-}6}$. For more general theories, we find that the constraints from Cepheid variable stars are currently more competitive than the bounds we obtain here but we are able to rule out self-screening parameters ${\ensuremath{\chi}}_{c}>{10}^{\ensuremath{-}6}$ for fifth-force strengths (coupling of the scalar to matter) as low as 0.05 the Newtonian force. This region of parameter space has hitherto been inaccessible to astrophysical probes. We discuss the future prospects for improving these bounds.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.002 | 0.005 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.000 |
| Bibliometrics | 0.001 | 0.002 |
| Science and technology studies | 0.000 | 0.002 |
| Scholarly communication | 0.001 | 0.001 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.001 | 0.001 |
| Insufficient payload (model declined to judge) | 0.001 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".